An artwork by Banksy shredded itself after selling for $1.3 million at Sotheby’s.

Bansky, Love is in the Bin, 2018. Sold for £1,042,000. Courtesy Sotheby’s.

Banksy’s iconic Girl With Balloon (2006) attracted feverish bidding in the room and on the phones, racing past its high estimate of £300,000 to hammer at £860,000, or just over £1 million ($1.3 million) with fees. As the gavel slammed, a siren rang out through the salesroom and everyone stood stunned as the Banksy canvas slid through the frame that it was contained in and emerged underneath—but shredded.

It seems that the art world’s biggest prankster concocted a scheme in which his work would get destroyed as soon as it was sold. The spray painted work of the girl with a red balloon, acquired directly from the artist, came in what the catalogue called “the artist’s frame”—a frame that was oddly thick for such a small work of street art.

A source at Sotheby’s, who spoke on the condition of anonymity, said that the Banksy camp had insisted on securing an unusually high number of seats for the sale. Some onlookers reported seeing one of these people with a device in his hand after the shredding happened, and that he was detained by security as he tried to leave.

“We have not experienced a work spontaneously shredding after it sells for a million pounds,” Sotheby’s Europe head of Contemporary Art, Alex Branczik said at the press conference.